BS 100 Points and Condenser

[ronjm]

I am having a little trouble figuring out the wiring for the points and condenser on my BS-100.
This stuff is a little before my time, and I can't find anything in the manuals describing the connections.

This is the way I currently have it hooked up, and getting no spark:

The black wire coming from ignition key switch soldered to condenser.
Wire from magneto ignition coil soldered to condenser.
A single wire goes from condenser to the bolt and nut on the contact breaker.
Green and White wire coming from the external ignition coil is screwed in behind the condenser with the same screw that holds the condenser in place.

The condenser has two solder posts that come off of it for connections.
I assume that it does not matter on which post any of these connections are made.
I soldered all three connections to both posts to make sure I had a good connection.

Does any of this sound correct to you, or am I completely backwards here?
Any other suggestions on getting spark? Any good way to test the coil to make sure its good?
Also, does anyone have any suggestions on spark plugs for this?

Thanks for any info.
Ron

[OldSwartout]

There are wiring diagrams in both the 90 service manual and in the 50,60,90,175 service manual available for download on this site.  However, they have pretty poor usefulness as they are B/W and the originals weren't all that great.  I think your wiring is correct (someone else chime in if they know otherwise).  Check that the point contacts are clean (really clean, not just blown off with a puff of air), the contacts are opening approximately .012-015 inch.  Make certain those connections to the condenser are not contacting the shell and grounding, and be certain the flywheel key is in place.  You have to spin the engine with the kickstarter, you can't generate a spark by spinning it over by hand while you're working on it (not fast enough).  You don't need the battery to generate spark in case you were wondering.

Standard plug is NGK B-8H or Champion L-57R.  B-8H or B-8HS plugs are easy to find in bike shops.

[ronjm]

Thanks for the quick reply. I agree those diagrams are really tough to read. Especially for someone like me who doesn't have a whole lot of experience with these old bikes. I cleaned the point contacts with contact cleaner,set the point gap properly, and put in a new plug. Still no spark.

Is there an easy way to check and see if the coil is bad, or any other tests I can do to see if it is getting power between the condenser and coil?

Thanks again, Ron

[reed]

ronjm
Have you checked the ign coil inside the fly wheel looking at the fly wheel its on the left side!
That was my problem on my 90 with no spark i checked out the points and condenser and wiring
It was the Ign coil inside the flywheel that goes to your coil on the frame etc.
Thanks.
Steve.

[ronjm]

The coil in the flywheel looks to be in good shape, but I don't know for sure.
There isn't any rust, and is very clean. Is there a way to test it?
That is definitely something to think about.
Thanks

[stickman]

I've found on 90's and 100's with no spark it was always the points were gapped to wide. I bought 4 bridgestones and the point gap was causing no spark on 2 of them,